Voyager 1 set to make interstellar history

This artist\'s concept shows NASA\'s two Voyager spacecraft exploring a turbulent region of space known as the heliosheath, the outer shell of the bubble of charged particles around our sun. (Courtesy NASA/JPL-Caltech)

You would have to be at least 40 years old with an incredible memory or a student of history to remember any of these events. And even if you were either or both of these, the launch of Voyager 1 and 2 may have been reinforced by the following images each of these spacecraft made in their exploration of the outer planets of the solar system.

But would you now know that they are still operational and have embarked on a new mission? These spacecraft literally rewrote the astronomy textbooks on Jupiter, Saturn, Uranus and Neptune. And they are poised to do so again but this time it will be about where the solar system ends and interstellar space begins.

Voyager – The Interstellar Mission, is designed to find out where the limits of the Sun’s influence ends and true interstellar space begins. These spacecraft, especially Voyager 1, are poised to answer this question perhaps in the very near future. The spacecraft remain healthy after all these years in space and are nuclear powered so they could theoretically operate until at least 2020. They are currently flying in unknown territory and making discoveries with each new data set returned to Earth.

Voyager 1 is the farthest of the two spacecraft and is currently 17.99 billion kilometers (11 billion miles) from Earth and traveling over 12 km (7 miles) per second. It is also the farthest spacecraft from Earth. It is predicted to be the first spacecraft in history to leave the Sun and solar system and enter true interstellar space — the realm of the stars.

Mission scientists think Voyager 1 is getting close to that historic moment because the spacecraft is encountering ever increasing “hits” from cosmic rays — interstellar radiation particles that come from distant stars. The cosmic ray count has increased significantly in June. With the travel time of Voyager 1’s radio signals being over 33 hours, it takes time to accumulate, process and then analyze the data. Scientists are currently studying the latest data return which will take several weeks.

Perhaps very soon we will hear the announcement that humanity has entered the stellar sea leaving behind the shores of the solar system and Sun. The Voyagers may outlast us as they could roam the stars forever. Both carry our calling card in the form of a golden record that identifies our location and is a Wikipedia of humanity and Earth.

Perhaps it is telling that in 1977 — the same year the Voyagers launched — a deep space signal was received by the radio telescopes of the fledgling Search for Extraterrestrial Intelligence (SETI) search known as the “WOW” signal. It has not been repeated nor is it known what caused it.

We live in a time where 55 years after the Space Age began we have two orbiting (and currently manned) space stations, a spacecraft on its way to Pluto — New Horizons — and humanity poised to have a robotic emissary set sail in interstellar space for the first time ever.

Will we ourselves ever sail on that ocean? Realistically, I don’t think so. A combination of the laws of physics and economics stirred by the politics of humanity make it seem unlikely. However we will have a presence among the stars that is enduring and that is an impressive legacy. Perhaps singularly so in the entire Cosmos.